<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button>临时数据</button>
    <button>有效数据</button>
    <script>
        var oBtns=document.querySelectorAll("button");
        oBtns[0].onclick=function(){
            document.cookie="age=20;name=sty";
        }

        oBtns[1].onclick=function(){
            var date=new Date();
            date.setDate(date.getDate()+10)
            document.cookie="sex=男;expires="+date;
        }
    </script>
</body>
</html>